diff --git a/.github/workflows/build_docker_nightly.yml b/.github/workflows/build_docker_nightly.yml
index ac78d58..44fb74d 100644
--- a/.github/workflows/build_docker_nightly.yml
+++ b/.github/workflows/build_docker_nightly.yml
@@ -12,6 +12,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        # Some repos have submodules that need to be part of the Docker image
         with:
           submodules: recursive